Could shuttle crew have been saved?
What might NASA have tried?
By James Oberg, SPECIAL TO MSNBC
HOUSTON -- As hindsights and "what-ifs" about the Columbia
disaster continue to accumulate, questions just won't go
away about what, if anything, NASA might have been able to
do to prevent the catastrophe had it known in advance how
bad was the damage to the wing.
THE MOVIE "APOLLO-13" is essentially a quite accurate
account of what Mission Control is capable of in a space
emergency. But most of the "emergency" procedures depicted
in the film weren't on-the-spot improvisations. They were
actually the fruits of a lengthy preparatory process in
which flight controllers, hardware engineers and
astronauts engage in "practice what-iffing" well in
advance of the flight.
I used to do it myself. Until leaving the job in 1997, I
flew shuttle missions from Mission Control. I was there
from the first drop tests of "Enterprise" to the first
orbital missions of "Columbia" in 1981. Then I helped
prepare and perform Challenger's first orbital maneuvers
and rendezvous missions with other satellites, all the
way to designing the orbital choreography of the initial
International Space Station linkup. We had our share of
worries and emergencies, and fast thinking usually made
the difference.
Leroy Cain, the NASA flight director on duty when
Columbia was lost, told me recently that "what-iffing"
was still a serious part of preparing for every space
mission.
"We went through many difficult failures and tried out
many recovery procedures in training," he said, "and that
prepared us to react constructively to a real crisis."
"In hindsight we now know that many of the things we
did were futile," he said. "On a different day, they
wouldn't have been."
But what could have been done? As the nature of the
Columbia catastrophe became clear, thousands of engineers
and space enthusiasts across the country joined Cain's
colleagues in trying to think of emergency procedures
that might have made a difference in the flight's
outcome.
Could the crew have inspected, or even repaired, the
damage? Could they have changed course and taken shelter
aboard the International Space Station? Was there a
"softer" way to hit the atmosphere, perhaps by leading
with the sound wing to give some relief to the damaged
one? Or could they have been rescued by another shuttle?
These ideas occurred independently to thousands of people.
SCENARIO ONE: A SPACEWALK
Take, for example, the idea of making a spacewalk to
inspect the area of suspected damage. NASA officials
said there was no proven method of doing that, since
the two spacesuits on board were only there for repairs
inside the payload bay. The crew had no jet backpacks
to fly around the shuttle, and no robot arm to position
themselves in sight of the bottom.
But the flight controllers I've talked with after the
disaster had no doubts they could have thrown together
a workable plan in a day or two, if asked. They would
have first completely checked it out in ground simulation
facilities, such as the giant water tank where floating
spacesuited astronauts mimic zero gravity, and then told
the crew what to do.
The trick would be to break some safety rules, but not
too many. One astronaut would unhook his or her safety
line from the shuttle, and the shuttle would fire its
thrusters to gently move about 200 feet away. It then
would roll 180 degrees, turning its belly to the
free-floating astronaut. Sure, he or she would probably
be slowly turning end over end in space. But he or she
would be able to eyeball the area of suspected damage
and take digital still images and zoomed video. Then
the shuttle would slowly roll another 180 degrees and
move back to retrieve the astronaut, like a giant
catcher's mitt enveloping a pop foul.
The flight controllers I talked to were horrified by
the Columbia disaster, but frustrated as well.
"We never got a chance to do what we do best," one
spacewalk expert lamented.
They had notebooks full of tricks, and minds trained to
generate new ones as needed. They just didn't have time,
this time, to even try.
But would such an inspection have revealed anything?
Whether through an astronaut's eyes or the lens of a
small self-propelled space spy camera, through a spy
satellite or ground-based surveillance telescope, any
insight would only have been as good as the actual view.
But what was there to see?
It appears that many of tiles came off the shuttle as it
flew over California, indicating that perhaps few, if
any, had originally been knocked completely free during
launch. Many others may have been damaged but remained
in place, which would deceive any visual inspection.
SPACE STATION OUT OF REACH
Flying over to the International Space Station, either to
get inspected by its crew, or to seek shelter there, was
never an option. Such a flight was physically impossible
because the orbits of the station and the shuttle were
in different directions through space. Where their paths
crossed, they were at angles too sharp for the shuttle's
limited rocket fuel to "turn the corner" and match orbits.
This situation wasn't the arbitrary result of blind choice.
The station is in a northerly orbit that allows access
from Russia's rocket base in Kazakhstan -- and that
access is now the station's only lifeline. The 16-day
Columbia mission was on a flight path designed to let it
launch and land during daylight at Cape Canaveral, a
powerful safety concern. The different requirements
demanded incompatible orbits.
SCENARIO TWO: FLYING DIFFERENTLY
Was there a gentler way to fly Columbia back into the
atmosphere? Cain was asked last week by reporters if
there were some alternate flying tricks that might have
relieved, at least in part, the thermal stress on the
left wing.
For example, if the left wing's thermal protection was
known to be compromised, could the shuttle enter the
atmosphere "crabbed" a little to the side? It would
scorch the heck out of the right wing that tilted into
the fire, but would it have made a difference for the
injured left wing?
"It's theoretically possible," Cain said, but added that
his teammates didn't think it would have worked because
such a move would have only a small effect on the heat
load.
"There are lots of things you can do," he said, "but
they don't necessarily solve your problem."
Worse, Cain said, "You just lead to potentially other
problems."
In this case, the "good" wing might have scorched through
its own tiles, damaged its steering jets or suffered some
other unanticipated damage. The balance of an unknown
pile of new risks vs. an uncertain current risk would
have been a decision nightmare.
SCENARIO THREE: RESCUE SHUTTLE
Another suggested scenario was rescue by another shuttle.
If Columbia could have stayed in space long enough, and
kept its crew alive long enough, perhaps the next
scheduled shuttle mission could have reached it.
This sort of space rescue is the stuff of which science
fiction movies are made -- and, in fact, one was, the
1969 film "Marooned." And it's the sort of "impossible"
contingency that the Mission Control team (and their
"bolt-turner" buddies on the launch crews at Cape
Canaveral) could really sink their teeth into.
Maybe the next shuttle, scheduled for a flight in March,
could have been accelerated to launch in less than two
weeks. Major shortcuts and added risks would have been
required. Fueling would have been more hazardous and
equipment less thoroughly checked. Work shifts would
have been long and would overlap, threatening procedural
oversights.
Meanwhile, once it was determined that Columbia was
badly -- even mortally -- wounded and could not safely
return to Earth, it could be sacrificed to save its
crew. Major systems could be powered down to conserve
electricity (they would be ruined by the cold of space,
but no matter).
Keeping the crew alive that long wouldn't have been easy.
The "long pole" would have been the chemicals to absorb
the astronauts' exhaled carbon dioxide. This is the gas
that kills people in closed spaces, such as children
trapped in old refrigerators. Carbon dioxide accumulates
in your blood and turns acidic, killing your brain cells.
There is only a finite supply of CO2-absorbing canisters
on any shuttle mission. Even if old ones were dug out of
the trash and CO2 levels were allowed to get so high as
to be painful, a cold-blooded calculus could have told
NASA that there wouldn't be enough air cleaning supplies
for all seven astronauts to wait for the earliest-
possible shuttle rescue. That's when "short-straw time"
arrives, and we move back into science fiction.
NO TIME
But on the day that Columbia was lost, there was no time
to invent a new procedure or to try something utterly
innovative and amazing that had been dreamed up in
anticipation of such a bad day. The continuing agony of
the Mission Control team, and of all space workers, is
to ask what indicators they overlooked or misinterpreted,
if any. Did they miss an opportunity to "what-if" their
way around the crisis, to try something, anything, to
break the chain of disaster? Or -- and it is a meager
consolation -- was this just the kind of bad day that
even Mission Control was powerless to forestall?
[James Oberg, space analyst for NBC News, spent 22 years
at the Johnson Space Center as a Mission Control operator
and an orbital designer.]
© 2003 MSNBC Corporation. All rights reserved.
*****
Newsgroups: sci.space.shuttle
From: "James Oberg"
Subject: Re: What might NASA have tried? SUPPLY SHIP?
Date: Wed, 19 Feb 2003 13:35:40 GMT
Now this is an intriguing idea. Throw something into
orbit close enough to Columbia that its crew could have
performed a rendezvous and retrieved it. Columbia would
have had to do it because nobody has off-the-shelf
automated rendezvous except Russia -- and they can't
launch into a 39 degree orbit.
You need to brief the crew on rendezvous, email up the
checklists (hey, we've done that -- in 1985), and
practice flying 'prox ops' -- maybe with a target
deployed on an EVA.
Launch into Columbia's orbital plane within three days
of alert, with a two-week supply of LiOH and food and
maybe even some batteries -- and manual handles on
the outside of the payload. Once in orbit -- below
Columbia -- the payload sits and waits. Columbia lowers
its orbit as needed to 'phase' properly and begin a
standard approach. It might take a day or two to wind
up station-keeping, then Columbia approaches and scoops
up the payload, and spacewalkers grab it. They stash
the stuff into the airlock and extend their lifetimes.
The long pole then becomes power. You can't immediately
'triage' the aft end of the vehicle -- you need to keep
the OMS/RCS for the rendezvous burns. This sucks even
more cryogens into the fuel cells for power to run
heaters.
Once you've gotten the goodie box -- and there is
propellant for multiple attempts -- you can shut down
the aft end and see how long you can sit at minimal
power mode, in the dark and cold, for rescue.
Neat-o!
