Saw this on twitter and couldn't find a ULA Starliner patch on the forum:QuoteNewest mission patch for @ulalaunch's #AtlasV launching @Boeing's #Starliner capsule! #welaunchedthathttps://twitter.com/ularocketman/status/852197019829522432
Newest mission patch for @ulalaunch's #AtlasV launching @Boeing's #Starliner capsule! #welaunchedthat
Aerojet Rocketdyne Successfully Completes Qualification Tests on Reusable Engine to Support Next Era of Human Spaceflight from the United StatesSACRAMENTO, Calif., April 20, 2017 (GLOBE NEWSWIRE) -- Aerojet Rocketdyne, Inc., a subsidiary of Aerojet Rocketdyne Holdings, Inc. (NYSE:AJRD), has successfully completed hot-fire qualification tests of an engine that demonstrates the ability to meet reusability requirements for Boeing's Crew Space Transportation (CST)-100 Starliner crew module propulsion system. The tests were conducted on Aerojet Rocketdyne's MR-104J hydrazine monopropellant engine in Redmond, Washington. For NASA service missions to the International Space Station, Boeing's Starliner spacecraft will carry up to four astronauts and time-critical scientific research."Our engineers have incorporated a unique design that will allow the MR-104 engine to be used on multiple missions, providing the reliability, cost-efficiency and reusability our customer needs to be competitive in the current commercial space environment," said Aerojet Rocketdyne CEO and President Eileen Drake. "We look forward to delivering the engines for the crew module and continuing our proud heritage of enabling astronauts to fly to the International Space Station from U.S. soil."The Starliner crew module propulsion system will use 12 MR-104J engines for reaction control to orient the vehicle during re-entry into the Earth's atmosphere. Prior to re-entry, attitude control is provided by the Service Module Engines, also provided by Aerojet Rocketdyne.The MR-104J, designed by Aerojet Rocketdyne, was developed and tested under the company's Commercial Crew Transportation Capability (CCtCap) subcontract to Boeing. Similar to other reaction control system engines, the MR-104J includes additional features to increase redundancy that meet critical requirements and improved strength to withstand multiple shocks at operating temperatures. The engine upgrades also provide reusability for Boeing as it certifies Starliner crew modules for multiple missions.Under the CCtCap subcontract to Boeing, Aerojet Rocketdyne will provide propulsion system hardware that includes Crew Module Reaction Control engines; Launch Abort Engines, Orbital Maneuvering and Attitude Control thrusters, and Service Module Reaction Control System thrusters. Boeing will assemble propulsion hardware into the Starliner spacecraft at its Commercial Crew and Cargo Processing Facility at NASA's Kennedy Space Center in Florida.Aerojet Rocketdyne is an innovative company delivering solutions that create value for its customers in the aerospace and defense markets. The company is a world-recognized aerospace and defense leader that provides propulsion and energetics to the space, missile defense and strategic systems, tactical systems and armaments areas, in support of domestic and international markets. Additional information about Aerojet Rocketdyne can be obtained by visiting our websites at www.Rocket.com and www.AerojetRocketdyne.com.
Tim Robinson @RAeSTimR 5m5 minutes ago1st Boeing CST-100 Starliner in construction here at KSC.
I'm not an engineer or scientist so forgive me / delete my post if it is in the wrong place, or the answer is obvious and I just need to go search more. Why is hydrazine monopropellant, still being used? My understanding is that it is pretty toxic. Perhaps it is relative inexpensive, thus gives very good thrust / control for the cost?I'm guessing that we just haven't developed propellant / engines that would be as cost effective and as usable. -S
Quote from: Sotar on 05/25/2017 10:12 pmWhy is hydrazine monopropellant, still being used? My understanding is that it is pretty toxic. Perhaps it is relative inexpensive, thus gives very good thrust / control for the cost?I'm guessing that we just haven't developed propellant / engines that would be as cost effective and as usable. No igniter is needed. Almost unlimited restarts are possible. Open a valve and pass N2H4 through a catalyst and, presto, instant reliable relatively cool thrust with no moving parts except for a valve or two. Put these thrusters on a satellite and they'll run for 15 or 20 years, maybe longer. See Voyager. They'll keep thrusting.Wikipedia gets this one right. It says "[e]ngineers choose monopropellant systems when the need for simplicity and reliability outweigh the need for high delivered impulse". Think about your life depending on that thruster, then underline that word reliability a few times. - Ed Kyle
Why is hydrazine monopropellant, still being used? My understanding is that it is pretty toxic. Perhaps it is relative inexpensive, thus gives very good thrust / control for the cost?I'm guessing that we just haven't developed propellant / engines that would be as cost effective and as usable.
1) In the early days of the space industry HTP and hydrazine competed with each other. HTP lost because the efficiency of the cathalist decreased with burntime. Hydrazine did not have this problem or they solved it early on. Hydrazine has a bit higher ISP, and also density ISP (if I'm not mistaken). This lead the space industry to use hydrazine and drop HTP.2) If I'm not mistaken, the problems with the durability of HTP cathalist packs has bean solved recently (several years ago). The problem is that the HTP engines havn't been flight tested. Hydrazine is space proven technology (TRL9). If I'm not mistaken, HTP thrusters havn't been used in space jet. They have been ground tested so they are TRL6/7 (right?)
HTP has long term storage issues.
... SpaceX Dragon v2 also uses hydrazine monopropellant thrusters. (Super) Draco
Doesn't NASA somewere have a tank where they have stored HTP at 4deg celcius for multiple decades. The HTP in that tank is stil stable. But I'm far from an expert on this, please correct me if I'm wrong.
Quote from: Rik ISS-fan on 05/31/2017 06:25 pmDoesn't NASA somewere have a tank where they have stored HTP at 4deg celcius for multiple decades. The HTP in that tank is stil stable. But I'm far from an expert on this, please correct me if I'm wrong.It was 90% HTP stored for 17 years in a vented barrel at 5 C by the FMC Corporation. They measured 90.5% concentration at 17 years.
@torybruno and I conducting demo of the @ulalaunch LC41 #AtlasV #Starliner Emergency Egress System. Crew safety is our top priority! 40+ MPH
Best ride in Florida. #AtlasV #Starliner @BoeingDefense
Tory Bruno Verified account @torybruno 2m2 minutes agoDecatur has completed #Starliner PCM-1's Forward Truss Ring. Another step closer to sending Astronauts to space from American soil.