|T O P I C R E V I E W|
|Philip||After the reentry of a Soyuz capsule a sonic boom is heard, but I wonder if the capsule itself deploys smoke markers after Soyuz descent module reentry?|
Before full parachute deployment, the Soyuz heat shield is jettisoned and maybe the smoke markers are related to this piece of hardware?
|Philip||Could the smoke trails be related to the separation pyrotechnics of the parachute lines?|
|Robert Pearlman||I think you might be referring to the venting of hydrogen peroxide from the spacecraft's control system prior to the jettison of the heat shield and soon after the main parachute deploys.|
NASA photographer Bill Ingalls caught the venting in a photo of the Soyuz MS-02 landing:
The first frames I shot had the Soyuz so small in the frame that I dismissed them. After a more careful review, and zooming in like crazy, I noticed that I had caught the hydrogen peroxide purge which I had never seen before.
|kyra||The opening of all the descent micro-thrusters and drainage valves is triggered by the same command that jettisons the heat shield in a nominal descent at 5.5 km altitude. (3.5 km altitude on the backup parachute system)|
What is vented is the residual of the original 29 to 31 kg of hydrogen peroxide.
|Philip||I know that once the main parachute is deployed, the smoke is the H2O2 venting process but I was talking about the very first smoke trails recovery crews on the ground spot so they get an idea of the location of the capsule. In fact smoke trails shortly after the sonic boom, probably related to the heat shield jettison...|
See 33 seconds onwards in this video.
|kyra||I've not seen anything like that before. I wonder if these are not from the Soyuz, but from airborne recovery forces to lead the recovery team in the right direction.|
|Lasv3||What you see in the video are the four segments of the Soyuz launcher first stage falling to earth and the people in the vehicles are the space scrap hunters collecting the precious materials in the steppe and selling them for profit.|
This is part of the "Space Tourists" DVD by Christian Frei covering the flight of Anousheh Ansari.
|Lasv3||Few more words to the "Space Tourists" documentary. It's Swiss made, it's 98 minutes long and it covers mainly the flight of Ms. Ansari. |
Author Christian Frei visited many places related to the Soviet/Russian spaceflight and some footage is really very rare. It's the visit of the space scrap metal hunters who made their living from collecting the precious materials they take from the fallen rocket stages which they sell then further, mainly to China.
The short sequence we can see in the video is the return of the four Soyuz first stage boosters after Ms. Ansari's launch from Baikonur. According to the author Mr. Frei he was the first person allowed to go with them to the steppe and take pictures and video footage during the search and dismantling of the rocket stages.
|Lou Chinal||Didn't the jettison of hydrogen peroxide cause the failure of one of the canopies on Apollo 15?|
|PowerCat||Apollo 15's parachute failure was due to the RCS Fuel Dump. Hydrogen peroxide was not one of the components.|
|Lou Chinal||Okay so Soyuz does not use hydrogen peroxide. But I'm sure whatever they do use is equally corrosive. It's a bad idea to dump any thing once the parachute is open.|
|Jim Behling||Soyuz does use hydrogen peroxide in the descent module. The comment was about Apollo.|
Losing a few parachute cords is better than an H2O2 tank exploding upon landing.