Thorsten
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An early morning low-inclination launch, it's still dark on the ground, but the bright SRB flame lights up the clouds...
Separation, and the Shuttle proceeds onward into the dawn light, everything nominal so far...
... but we lose an engine. TAL abort is declared immediately, and the OMS propellant dump is started. The Shuttle starts to proceed towards Banjul, the standard TAL site for low inclination. Two engines are quite enough to keep us on the desired trajectory, so Africa, here we come!
Leaving the US coast, there's already light on the clouds over the Atlantic ocean. If you look closely, you can distinguish the bright OMS and RCS flames of the propellant dump and the nearly invisible flame of the main engines.
Darn - we've lost a second engine. Droop guidance engages automatically, pitching the Shuttle up steeply to avoid letting the trajectory fall below 275.000 ft (at this altitude, the ET might blow due to heating). To assist the maneuver, the last engine is throttled up to 109% performance. As the engine consumes propellant, the Shuttle gets lighter so eventually even a single engine can keep us from falling down. Likewise Single Engine Roll Control (SERC) has engaged - by gimbaling the last engine we can control pitch and yaw, but no longer roll, so the RCS jets now fire to do the job. The resulting roll is very very sluggish, so we do not roll to heads-up attitude with the ET attached.
... and droop guidance has disengaged we're back on the trajectory. But the droop maneuver costs a lot of propellant, so we won't be able to make it even to Banjul. We're going to have an OPS 3 entry into the atmosphere, which is good, they're less wild than the OPS 6 version, but still - a bailout somewhere over open water is going to be a really rotten prospect, but there's Cape Verde a few hundred miles before Banjul - so we change the TAL site to there and keep our fingers crossed.
MECO with little propellant to spare - the next minute is very hectic and shows why there's a commander and a pilot needed - the commander rolls the Shuttle to proper entry attitude, the pilot checks that the ET umbilical doors are properly closing, that the MPS propellant dump is initiated, and then the commander changes to OPS 3 before the atmosphere is felt too much.
The heat shield is already glowing before we reach proper entry attitude.
Turns out we're still a bit far off - the last resort is to activate low E flight rules. This means rough phugoids - the Shuttle bounces into the atmosphere, back out and falls back in - but this way we squeeze every mile we can possibly get out of the energy we have. The display flashes a high-g warning, entry is still on the rough side...
ENTRY TRAJ display shows the rather strange signature of the phugoids...
... but eventually we reach the nominal trajectory and can de-activate low E flight rules - back to a nominal entry then - we're going to make it to a solid runway after all, no bailout over open water.
The Shuttle banks sharply using nominal entry guidance.
Clouds over water seen from the Commander perspective... also note that on the SPI we can see trim is really off, we need lots of ailerons to keep in attitude. That's because we're flying an abort, there was no time to dump the FRCS propellant... About now is the time to activate the ammonia boilers to provide cooling of the systems at lower altitudes...
TACAN of Cape Verde is acquired, air data probes are out, QNH at the landing site has been transmitted, a rather surprised controller at Amilcar Cabral International Airport has been told that he'll soon see a Shuttle coming in, all traffic around the airport has been diverted - and the Commander is seeing a nominal TAEM
Turning into the HAC, morning light playing across the displays...
It's a bit cloudy, broken cover, but we can't be picky now, can we?
Descending into final approach...
... and landing at Amilcar Cabral International Airport... Well, we were hoping to get into space today, but at least we didn't end up swimming in the Atlantic...
Separation, and the Shuttle proceeds onward into the dawn light, everything nominal so far...
... but we lose an engine. TAL abort is declared immediately, and the OMS propellant dump is started. The Shuttle starts to proceed towards Banjul, the standard TAL site for low inclination. Two engines are quite enough to keep us on the desired trajectory, so Africa, here we come!
Leaving the US coast, there's already light on the clouds over the Atlantic ocean. If you look closely, you can distinguish the bright OMS and RCS flames of the propellant dump and the nearly invisible flame of the main engines.
Darn - we've lost a second engine. Droop guidance engages automatically, pitching the Shuttle up steeply to avoid letting the trajectory fall below 275.000 ft (at this altitude, the ET might blow due to heating). To assist the maneuver, the last engine is throttled up to 109% performance. As the engine consumes propellant, the Shuttle gets lighter so eventually even a single engine can keep us from falling down. Likewise Single Engine Roll Control (SERC) has engaged - by gimbaling the last engine we can control pitch and yaw, but no longer roll, so the RCS jets now fire to do the job. The resulting roll is very very sluggish, so we do not roll to heads-up attitude with the ET attached.
... and droop guidance has disengaged we're back on the trajectory. But the droop maneuver costs a lot of propellant, so we won't be able to make it even to Banjul. We're going to have an OPS 3 entry into the atmosphere, which is good, they're less wild than the OPS 6 version, but still - a bailout somewhere over open water is going to be a really rotten prospect, but there's Cape Verde a few hundred miles before Banjul - so we change the TAL site to there and keep our fingers crossed.
MECO with little propellant to spare - the next minute is very hectic and shows why there's a commander and a pilot needed - the commander rolls the Shuttle to proper entry attitude, the pilot checks that the ET umbilical doors are properly closing, that the MPS propellant dump is initiated, and then the commander changes to OPS 3 before the atmosphere is felt too much.
The heat shield is already glowing before we reach proper entry attitude.
Turns out we're still a bit far off - the last resort is to activate low E flight rules. This means rough phugoids - the Shuttle bounces into the atmosphere, back out and falls back in - but this way we squeeze every mile we can possibly get out of the energy we have. The display flashes a high-g warning, entry is still on the rough side...
ENTRY TRAJ display shows the rather strange signature of the phugoids...
... but eventually we reach the nominal trajectory and can de-activate low E flight rules - back to a nominal entry then - we're going to make it to a solid runway after all, no bailout over open water.
The Shuttle banks sharply using nominal entry guidance.
Clouds over water seen from the Commander perspective... also note that on the SPI we can see trim is really off, we need lots of ailerons to keep in attitude. That's because we're flying an abort, there was no time to dump the FRCS propellant... About now is the time to activate the ammonia boilers to provide cooling of the systems at lower altitudes...
TACAN of Cape Verde is acquired, air data probes are out, QNH at the landing site has been transmitted, a rather surprised controller at Amilcar Cabral International Airport has been told that he'll soon see a Shuttle coming in, all traffic around the airport has been diverted - and the Commander is seeing a nominal TAEM
Turning into the HAC, morning light playing across the displays...
It's a bit cloudy, broken cover, but we can't be picky now, can we?
Descending into final approach...
... and landing at Amilcar Cabral International Airport... Well, we were hoping to get into space today, but at least we didn't end up swimming in the Atlantic...
