The Last Flight

(Article accepted by major spaceflight publication)

The Space Shuttle era is coming to an end. For decades the winged Orbiters have symbolized humanity’s reach into Space. For American astronauts, the Shuttle held monopoly on their ability to reach orbit. The Columbia accident of 2003 led to a new Vision for the Moon, Mars and Beyond. With the coming of Orion and other spacecraft, the Shuttles are scheduled to retire in 2010.

Cosmic rays represent some of the biggest mysteries in science. The most energetic particles ever found, they may hold the key to mysteries like antimatter and “dark” matter. A new international experiment, the Alpha Magnetic Spectrometer has been built to study cosmic rays. Carried aloft by Shuttle and mounted on the Space Station, AMS would be one of the Station’s key experiments.

As the year 2010 nears, a conflict has developed between science and program. Congress and the science community want an additional flight for AMS. Eager to retire Shuttle, some in NASA would prefer that the experiment be grounded. One possible solution is simple, safe and already being planned for.

Cosmic Rays and AMS

Though they bombard Earth constantly, relatively little is known about cosmic rays. First discovered by balloon experiments in 1912, these particles present some of the biggest mysteries in science. For decades the very origins of cosmic rays were a mystery. They can have enormous energies, far higher than those produced in human accelerators. The highest energy cosmic rays, nicknamed "Oh My God particles,” defy today’s physics to explain. Ultra-high energy cosmic rays may have originated at a time near the Big Bang, when even the speed of light may have been different.

As one example, nearly everyone has experienced the power of a thunderstorm. We are taught in school that lightning originates from static buildup within storm clouds. What triggers the discharges is unknown. Since cosmic rays fall nearly steadily across Earth's surface, some researchers have suggested that cosmic rays are the cause of lightning! That may be one more example of how Space science affects life on Earth.

The Alpha Magnetic Spectrometer is the most ambitious physics experiment designed for ISS. From its perch on the S3 Upper Inboard Payload Attach Site, AMS will intercept cosmic rays from Space. The project was first proposed in 1995, shortly after cancellation of the Superconducting Supercollider. As conceived by Nobel laureate Samuel Ting, AMS would explore energies far greater than Earthly accelerators. While the Large Hadron Collider can produce particles of 10^12 electron–volts, cosmic rays have energies in excess of 10^20 electron-volts.

The heart of AMS is a two-ton superconducting magnet, cooled to a temperature of only 1.8 degrees Kelvin. The paths of charged particles are bent by magnetic fields. As in a bubble chamber, scientists can identify different particles by their tracks. For instance, the tracks of matter and antimatter would be bent in opposite directions. Study of antimatter particles would offer clues as to why our Universe is made mostly of matter.

One of the most ambitious physics experiments ever built, the Alpha Magnetic Spectrometer is international in scope. Building AMS has employed 500 researchers from 16 nations. After a cost of 1.5 billion, the device is nearly completed. A prototype AMS-01 visited Space with STS-91 in 1998, returning data that validated the concept. During 2008 AMS will be moved from CERN to Kennedy Space Center for launch. Unfortunately, plans and lives were cut short by Columbia.

Shuttle Retirement

If NASA had known about the damage to Columbia’s Thermal Protection System, there would have been a small but fighting chance of rescue. While STS-107 was in orbit, Atlantis was being readied for STS-114. If certain safety protocols had been waived, she could have been launched early on a rendezvous attempt. Space would then have seen its greatest drama since Apollo 13. As the world below watched breathlessly, for the first time in history one spaceship would try to rescue another.

If her crew were evacuated, Columbia would have been left to her fate. She would have been boosted into a higher orbit to await another rendezvous. Possibly a way would have been found to repair the damage and return Columbia to service. More likely her orbit would have decayed until she met her end in the atmosphere.

Since return to flight in 2005, the biggest concern is another Columbia accident. Batteries of cameras on the ground and spacecraft now monitor every launch for foam strikes. Before and after docking each Shuttle is minutely inspected for damage using the Orbiter Boom Sensor System. Each mission carries some risk of TPS tiles being lost.

If damage were found that prevented safe reentry, a Shuttle crew would evacuate to the Station. A Contingency Shuttle Crew Support (CSCS) mission would Launch On Need to bring the crew home. Since the Station has never hosted two Shuttles simultaneously, the damaged Orbiter would be jettisoned before the rescue mission docked.

In the aftermath of Columbia, every remaining Shuttle flight was directed toward completing ISS. To make way for Constellation, the Shuttles were scheduled for retirement in 2010. Despite its expense, importance to science and international partners, the Alpha Magnetic Spectrometer was taken off the launch manifest. Studies have since shown that Shuttle is the only feasible vehicle for carrying AMS into Space.

Hubble Servicing Mission STS-125 poses its own challenges. HSM-4 was removed from the manifest following Columbia, but restored after pressure from the public and Congress. Evacuating to ISS from Hubble’s orbit will not be possible. As Atlantis ascends from Pad 39-A, Endeavour will be poised on Pad 39-B for Launch On Need. At the conclusion of HSM-4 Endeavour will be moved from 39-B, which will then be modified for the Ares 1-X test.

At this writing, Contingency Logistics Flights STS-132 (Discovery) and STS-133 (Endeavour) are scheduled for launch April 8 and May 31, 2010. After flight Discovery will re-enter the Orbiter Processing Facility and begin preparations for Launch On Need. A new External Tank ET-138 and two Solid Rocket Boosters must also be prepared. If STS-133 needs no rescue, those expensive pieces of hardware will go unused. Launching 7 months before the end of 2010, STS-133 may be the last Shuttle mission.

Many in the Space community are concerned about the “gap” after Shuttle retirement. Scientists are eager to see AMS fly on Shuttle. Without AMS, the Station is open to charges that it lacks scientific purpose. The 15 nations that have funded AMS wish to see the US fulfill its commitment. On June 18, 2008 a new NASA authorization bill passed the House of Representatives by an overwhelming 409-15 margin. In addition to increasing NASA funding, H.R. 6063 directs an additional Shuttle flight for AMS. As they supported Hubble Space Telescope, the people have spoken in support of science.

STS-134

A scenario for an AMS mission is described here. It is similar to most Shuttle flights with one notable exception. The rescue contingencies previously described all include retiring the damaged Orbiter in Space. Prior to the Shuttle era, NASA threw away nearly all its spacecraft. This may represent a simple, safe way to launch AMS while ending the Shuttle program.

The AMS mission would bring new duties for ISS crew. During 2009 the Station will establish a permanent six-person capability. Three-person expeditions or “increments” will arrive and depart via Soyuz. To prepare for AMS, one increment would temporarily be reduced to two persons. A Mission Specialist would arrive in a Soyuz, along with a Russian pilot who would join the ISS increment. Four persons would then be aboard to welcome the Shuttle, supported by two Soyuz spacecraft.

AMS would fly aboard an Orbiter already prepared for STS-133 rescue, using the External Tank and the Solid Rocket Boosters already purchased. A Commander and Pilot in the flight deck would be responsible for docking with the Station. For EVA the Orbiter would bring the normal complement of three Extravehicular Mobility Units (spacesuits.) The Mission Specialist would be responsible for installing AMS assisted by the Pilot, with the ISS crew available for EVA support.

The Commander, Pilot and Mission Specialist would return to Earth by Soyuz. This removes the risk of a Columbia accident, and the requirement to prepare another Shuttle for Launch On Need. (Hopefully the Soyuz problem of ballistic entry will be solved by 2010.) After its last mission is complete, the Orbiter will no longer be needed.

Concerning spacesuits, three Extravehicular Mobility Units would add to the ISS collection. The EMU was designed for Shuttle and is not cleared for Soyuz or Orion. Once the Shuttles stop flying the ISS is currently due to have just four EMU's onboard. Since there is no precedent for EMU’s lasting over a 5-year gap, the additional suits would be invaluable. Any Shuttle visit to ISS is valuable for extra small payloads. STS-124 was especially welcome for bringing parts to repair the toilet.

At the mission’s conclusion the crew would arm the Orbital Maneuvering System, exit to ISS and ceremoniously close the hatch. Mission Control in Houston can command the Orbiter to separate, maneuver and fire the OMS engines. A tail-first reentry over the Pacific would likely be chosen. In 50 years dozens of unmanned spacecraft and boosters have broken up over oceans without a single injury. The AMS mission would be a memorable end to the Shuttle era.

The Logical Thing To Do?

Safety is a primary concern of Shuttle operations. Unlike most other Space flights, the AMS mission has redundant rescue capability. At no point does the total number of people aboard ISS exceed the six-person capacity of the two Soyuz. In an emergency, the Shuttle will still be able to evacuate all six crew.

Because an Orbiter, External Tank, SRB’s and launch facilities must be prepared for STS-133 rescue, adding the AMS mission would be relatively inexpensive. The Mission Specialist and her crewmates would ascend and return in Soyuz flights already purchased. Returning by Soyuz avoids the expense and risk of landing an Orbiter on Earth. Along with Enterprise, which today sits in the National Air and Space Museum’s Udvar-Hazy facility, two Orbiters would be available for display. For the final mission, retiring an Orbiter in Space is an unusual but logical step.

Aside from safety issues, the cost of recovering an Orbiter is many millions of dollars. The Shuttle Landing Facility at Kennedy Space Center and the alternate runway at Edwards Air Force Base must be prepared and the airspace cleared. Helicopters and chase planes must be deployed for rescue and security. At each location, a land armada of 20-30 specialized vehicles and 150 trained personnel also stand ready. Their jobs include disembarking the astronauts, “safing” the Orbiter and removing its explosive propellants. The Edwards Space Shuttle Recovery Team alone has several hundred members. After an Edwards landing, the Shuttle must be mounted atop its 747 carrier and flown to an Orbiter Processing Facility at KSC. There an additional Orbiter, External Tank and Solid Rocket Boosters must be prepared for Launch On Need in case the reentry is aborted. For the Shuttle program, the price of reusability is high.

While two Orbiters have been lost in flight, no precedent exists for retiring a Space Shuttle on Earth. The costs of safing an Orbiter and putting it on display are unknown but probably beyond the means of most museums. Only a few sites have a history of operating Shuttles. Kennedy Space Center could convert an Orbiter Processing Facility for Shuttle display. The Manned Spaceflight Center in Houston and the Air Force Flight Test Center Museum at Edwards would also be competing locations. Kennedy and Edwards both have the advantage of a Mate/Demate facility for an Orbiter and 747. Along with the two carrier aircraft, many Shuttle mockups and parts remain for museums.

Future generations will look upon the Orbiters with wonder. Starting with dreams of a reusable Spaceplane, the Shuttle has maintained humans in Low Earth Orbit for 3 decades. This period has provided both hope and tragedy. Hundreds of trained astronauts have reached LEO via the Shuttle Orbiters. As the year 2010 approaches, private industry is prepared to ferry humans into orbit and NASA is ready to again move beyond. The Space Shuttles will long remain as symbols of an era.

A Sacrifice for AMS?

Shuttle Discovery photographed from ISS during STS-124. Below is the KIBO pressurised module, and to the right is the Japanese logistics module. Discovery undocked from ISS at 0742 EDT (see below) and is due to return Saturday. The Hubble Space Telescope repair mission is scheduled for October, but may be delayed due to launch damage to Pad 39-A. Previously STS-125 was to be Atlantis' last mission, but she may be saved for STS-128 and STS-131. The three surviving Shuttles are scheduled for retirement.

Today NASA is due to announce a decision on the Constellation Space Suit Program. While we are waiting, the US Congress is considering a new NASA authorization bill. H.R. 6063 will give NASA 2.9 billion more than the White House requested. It also orders one more Shuttle flight to deliver the Alpha Magnetic Spectrometer. NASA administrators are resistant to AMS because of safety concerns and delays in implementing Constellation. They are eager to junk the Shuttles and make way for Orion.

There may be a way to make everyone happy. It would be cheaper, get AMS into Space without any chance of a Columbia accident, and accelerate retiring of Shuttle. Since this would be the last flight, we could use the Shuttle to deliver AMS and leave it in Space. This follows a long Navy tradition of scuttling the ship to save the mission.

While most Shuttle flights carry seven, nominal mission STS-134 could be accomplished with a crew of three: Commander, Pilot and Mission Specialist. Attaching AMS to the Station will require two crewmembers and multiple EVA's. The Mission Specialist will be responsible for installing AMS assisted by the pilot, with the ISS crew available for extra help. Once installation is complete, the Shuttle is no longer necessary.

The crew of three will return by Soyuz. There are extra seats available on returning Soyuz flights, which is how Expedition Six returned after Columbia. Hopefully the Soyuz problem of ballistic entry will be solved by 2010. NASA may even do like Sergei Brin and charter an extra Soyuz mission.

Concerning Spacesuits, the three EMU's brought by the mission would add to the ISS collection. The current EMU was designed for Shuttle and will not fit in Soyuz or Orion. Once the Shuttles stop flying the ISS crew will have to make do with the EMU's they have until those suits wear out. Any additional Shuttle mission will be valuable in bringing extra small payloads-perhaps the ISS toilet will need more parts.

At the conclusion of its mission the Shuttle will be stripped of useful equipment and cut loose from ISS. This should be done shortly before a station-keeping maneuver, which will boost ISS into a higher orbit and leave the Shuttle behind. Atmospheric drag will take care of the rest. While Mission Control has limited ability to control an unmanned Shuttle, hopefully they can steer her to come down in the Pacific.

Columbia showed us what would happen next. Uncontrolled, the Shuttle would glide in as far as ground control would take it. At a certain point she would tumble out of control and break up. Like Columbia or Captain Kirk's Enterprise, her death would be a spectacular event seen from Earth.

Since NASA is so eager to end the Shuttle programme, they might consider the same profile for STS-133. Endeavour's mission to deliver Express Logistic Carriers 3 and 4 could also be accomplished without Shuttle return. Abandoning the Shuttle would ensure that the program is not continued. Museums that were hoping to have Shuttles in their collections would be most disappointed, but the cost of "safing" a Shuttle is quite high. Giving the museums Shuttle mockups would be far cheaper, and we could easily include parts from the "real" Shuttles.

Leaving a Shuttle would be a simple and safe way to end the program while carrying AMS into Space. There may be technical details overlooked here-NASA personnel are welcome to point them out. Presently NASA is reluctant to make any plans concerning AMS; that will change if Congress gets their way. This would be a fitting end to the Shuttle era, opening the way for the future.

The Constellation Space Suit contract has just been awarded to my friends at Oceaneering. More about this soon!

AMS vs JDEM?

Michael Griffin spoke on another subject to the American Astronomical Society this month. After 1.5 billion has been spent by 15 nations. the Alpha Magnetic Spectrometer is sitting in a clean room without a flight to ISS. On December 14 Alan Stern told me personally that it was grounded for life. Recently Congress directed NASA to study getting AMS into Space. Some of Griffin's comments:

"AMS could be placed in orbit by other means, either as a free-flyer or delivered to ISS by means of automated systems, as with ISS logistics cargo. Such alternative means will not be cheap; current estimates are on the order of 400 million. NASA lacks the budget allocation for such a mission, so, should it be directed by Congress, it would have to "come out of hide". Astrophysics hide. Thus, I will be asking the National Academy to assess the priorities of the missions in the Beyond Einstein program set forth in their report last September, where the Joint Dark Energy Mission was recommended to be launched first, compared to the scientific priority of the AMS."

Among the insular world of scientists, an expensive mission to study imaginary "dark energy" is still popular. It would cost at least 1.1 billion and find nothing. AMS could be sent into orbit for relatively little and find the highest energy cosmic rays. A launch would please European and Japanese partners to no end. What will the scientists choose?

AGN's and Cosmic Rays

Last week the phenomenon of ultra-high energy cosmic rays was linked to giant Black Holes. The most energetic particles in the Universe, more powerful than those produced by human accelerators, are in cosmic rays. Scientists don't even know how energetic these particles can get. Ultra-high energy cosmic rays have been nicknamed "Oh My God" particles.

Using the Auger Observatory in Argentina, astronomers have linked the origin of some high-energy cosmic rays to active galactic nuclei. AGN's are energetic cores of galaxies powered by supermassive Black Holes. Scientists still don't know how the galactic cores are formed. Size of a primordial singularity is limited by a horizon distance related to the speed of light. Supermassive Primordial Black Holes ar more indications of a changing speed of light.

The most energetic cosmic rays don't reach Auger at all, but are stopped by Earth's upper atmosphere. Here they scatter into a shower of secondary particles. Source of the electrical discharges in lightning storms has been another mystery. Since cosmic rays fall on Earth constantly, some have suggested that they are the source of lightning. If true, it is one more example of how are lives are intertwined with Space.

To observe the most energetic cosmic rays, we must go beyond the atmosphere. Spacecraft like SWIFT and GLAST can detect these rays and possibly locate their source. Sources of many cosmic rays are still unidentified. They could be the explosions of tiny primordial Black Holes, or possibly something else. We are only begiining to learn about cosmic gamma rays.

CERN claims to have detected a fountain of antimatter erupting from the core of our Milky Way galaxy. Their "antimatter flash" video is above. More news in the new Carnival of Space!

Alpha Magnetic Spectrometer In Limbo

Now that Atlantis has safely returned to Earth, she only has two scheduled missions left. Her last flight, STS-125, is scheduled for September 10, 2008. That will be the servicing mission for the Hubble Space Telescope. As part of the mission a docking adapter will be installed, making future servicing missions by Orion possible. Refurbishing HST was nearly cancelled, but was saved by support from both scientists and the public.

The Alpha Magnetic Spectrometer is designed to be attached to ISS. It incorporates superconducting magnets to detect cosmic rays striking Earth. It may find the signatures of antimatter in the early Universe. A Space Station is an unprecedented platform for such observations. AMS is a collaboration of 16 countries who have spent 1.5 billion US on the project. It is the most important physics experiment planned for ISS.

Though they strike Earth constantly, relatively little is known about cosmic rays. These particles reach energies far higher than any human accelerator can achieve. The highest energy cosmic rays, nicknamed "Oh My God" particles, have energies far greater than physics can explain. These particles may have originated at a time near the Big Bang. Their immense energies are one more indicator that the speed of light has slowed.

Nearly everyone has experienced the power of a thunderstorm. We are taught in school that lightning originates from static discharges within storm clouds. What triggers those discharges is unknown. The tracks of cosmic rays, striking and scattering particles in the atmosphere, are very similiar to lightning. Some researchers have suggested that cosmic rays are the cause of lightning! Since cosmic rays fall nearly steadily across Earth's surface, that is a hypothesis that needs to be tested. If cosmic rays cause lightning, that is one more example of how our lives are intimately entwined with Space.

The AMS is nearly completed and sitting in a clean room. Unfortunately, with the shuttle program scheduled to end in 2010, there is no longer a flight scheduled to take AMS into Space. Alternatives have been studied, but adapting the experiment to another spacecraft would cost hundreds of millions. Grounding the experiment would be a major disappointment for scientists and international partners. Physicists have not given up; the experiment is still scheduled to be received by NASA in 2008 and prepared for flight.

There are one, possibly two hopes left. NASA has allowed two "contingency" flights to ISS in case something goes wrong with a scheduled mission. If these flights are not used up, one of them could be used to orbit AMS. More ISS missions are a good thing, for they allow more supplies and crew changes. This may mean extending the shuttle program past 2010, but with all the delays that may happen anyway.

Adding a flight will also narrow the "gap" between shuttle retirement and the first Orion flights. If shuttle is retired in 2010 and Orion does not fly until 2013 (2014? 2016?) it will be the longest gap in US human spaceflight since 1975-81. During that period ISS would be completely dependent on Russian spacecraft. We can only hope that private spacecraft can help fill the gap.

Just as scientists and the public successfully lobbied to repair Hubble, now is the time to start lobbying for AMS. As before, NASA may examine alternatives before concluding that a shuttle mission is needed. This is a very important experiment that international partners have already paid for. Leaving AMS on the ground would remove one scientific justification for ISS. The Alpha Magnetic Spectrometer deserves to fly.