LIVE: Progress M-16M Launch, Docking, Departure - August, 2012 - Feb, 2013

[Danderman]

http://www.roscosmos.ru/main.php?id=2&nid=18770

Apparently, the Soyuz-U booster is in Baikonur.

[Targeteer]

The color and texture of the nozzle linings/insides on photo 3 make me think they're copper--are they?

[anik]

The launch and docking are planned on August 1st.

[Danderman]

I just solved a long standing mystery about the Russian Progress vehicle - I have asked about this in the past and no one could provide the answer, but now I can.

The Progress M class vehicle can carry 880 kg prop in its rear section, and another 880 kg of prop in the center section (but rarely does, due to carrying cargo in the front). The question is: given this prop budget, how many tries can Progress make to dock with a space station?

During the 1990s, the Progress M-24 mission made it on the third try to dock with Mir, using the TORU system. At the time, mission controllers described this as the "last chance"; this has always puzzled me, since the Progress was carrying well over a ton of usable propellant, and each docking attempt used only about 150 kg of prop - there seemed to be plenty of prop for a 4th or 5th attempt, but for some reason, 3 was the limit. No one has ever explained why Progress is only good for 3 attempts at docking, during a nominal mission.

The answer is that after depletion of prop during 3 docking attempts, the center of gravity of the Progress moves too far forward to safely allow further docking attempts.

When a Progress departs from ISS, and is required to redock with ISS, there is more margin because the cargo has been removed and replaced with trash - this means there is less mass in the front of Progress, as trash is lighter than cargo. With a lighter load in the front, more prop can be depleted and maintain the vehicle c/g.

[baldusi]

Every day you learn something new! Thanks for your input.
BTW, that does makes it interesting to think if a wider body Progress couldn't position the tanks to improve the control authority due to c/g problems.

[Danderman]

Every day you learn something new! Thanks for your input.
BTW, that does makes it interesting to think if a wider body Progress couldn't position the tanks to improve the control authority due to c/g problems.

The thruster configuration would have to be changed to handle the lateral dispersions with a wider body; if you are going to change the thrusters, you can handle the longitudinal dispersions without going to a wider body.

There was some talk that the upcoming "MC" variant would address some of these issues, as Progress and Soyuz have very little control authority unless everything is perfectly loaded and in place.

[Fuji]

August 1, Wednesday
3:15 p.m. - Coverage of the Launch of the ISS Progress 48 Resupply Ship to the ISS (Launch scheduled at 3:35 p.m. ET)
8:45 p.m. - Coverage of the Docking of the ISS Progress 48 Resupply Ship to the ISS (Docking scheduled at 9:26 p.m.)
http://www.nasa.gov/multimedia/nasatv/MM_NTV_Breaking.html

[Danderman]

Progress M-16M will perform a fast-rendezvous profile with four maneuvers on orbits 1-3 and five-six maneuvers on orbits 3-4 for docking on orbit 4.

[TJL]

Progress M-16M will perform a fast-rendezvous profile with four maneuvers on orbits 1-3 and five-six maneuvers on orbits 3-4 for docking on orbit 4.

Similar to Gemini docking with Agena Target Vehicles in 1966.

[anik]

The launch is planned at 19:35:15 UTC on August 1st.

[Fuji]

Progress 48P 4-Orbit Rendezvous: Plans are underway at TsUP-Moscow to attempt the upcoming resupply flight of Progress M-16M/48P (#416) with a new mission profile involving only 4 catch-up orbits around the Earth instead of the usual 34 orbits. If successful, this would save about 45 hrs (see launch/docking times, below). If after launch the mission profile is transitioned from 4 hrs to 34 hrs, docking time would change to the latter profile.

08/01/12 -- Progress M-16M/48P launch [4-orbit RDVZ] ~3:35pm EDT
08/01/12 -- Progress M-16M/48P launch [34-orbit RDVZ] ~3:38pm EDT
08/01/12 -- Progress M-16M/48P docking [4-orbit RDVZ] ~9:24pm EDT
08/03/12 -- Progress M-16M/48P docking [34-orbit RDVZ] ~6:14pm EDT
http://www.nasa.gov/directorates/heo/reports/iss_reports/2012/07042012.html

[jacqmans]

July 13, 2012.
 A meeting of the Technical management

At Baikonur launch site the preparations continue for the launch of Progress M-16M cargo vehicle under the International Space Station program.

The Technical Management meeting took place, which made a decision to fuel Progress M-16M cargo vehicle with propellant components and compressed gases.

http://www.energia.ru/en/iss/iss32/progress_m-16m/photo_07-13.html

[zt]

From the recent NSF article on Soyuz TMA-05M:

This Progress will be taking a short cut to Station, cutting the arrival time down from the traditional two days, to just four orbits, potentially laying the foundations for a much shorter mission timeline prior to docking for future Soyuz astronauts.

Can someone explain why didn't they do this many years ago, what changed? I thought the approach to ISS took two days because the vehicle didn't have enough thrust or propellant to do a faster approach and the rocket couldn't put it in a high enough initial orbit. But I don't see any mention of this progress having new engines, more fuel or launching on a new version of Soyuz.

[Olaf]

From the recent NSF article on Soyuz TMA-05M:

This Progress will be taking a short cut to Station, cutting the arrival time down from the traditional two days, to just four orbits, potentially laying the foundations for a much shorter mission timeline prior to docking for future Soyuz astronauts.

Can someone explain why didn't they do this many years ago, what changed? I thought the approach to ISS took two days because the vehicle didn't have enough thrust or propellant to do a faster approach and the rocket couldn't put it in a high enough initial orbit. But I don't see any mention of this progress having new engines, more fuel or launching on a new version of Soyuz.

What are the disadvantages of this flight profil?

[Danderman]

AFAIK, about every 6 months or so, the ISS will fly over a launch site so that a vehicle launched from that site can rendezvous with the station if launch is made at a very precise time. If that time is missed, it would be another 6 months before another quick rendezvous can be made.

However, the 2 or 3 day rendezvous approach allows for launch to the ISS every day.