Rocket 3.2 Orbital Launch Attempt | Astra Rocket 3.2

Featured image credit: Astra/John Kraus

Launch Window/Lift Off Time
(Subject to change)
NET December 15, 2020 – 19:00-22:00 UTC | 11:00-14:00 PT
Mission Name
Orbital Launch Attempt 2
Launch Provider
(What rocket company is launching it?)
Astra
Customer
(Who’s paying for this?)
Astra
Rocket
Rocket 3.2, the second iteration of Astra’s Rocket 3 series
Launch Location
Launch Pad 3B, Pacific Spaceport Complex in Kodiak, Alaska
Payload mass
Up to 25 kg (55 lb)
Where are the satellites going?
To a Low Earth Orbit (LEO) of 380 km,
at an inclination of 98.1°
Will they be attempting to recover the first stage?
No, this is not a capability of Astra.
Where will the first stage land?
The first stage will crash into the Pacific Ocean
Will they be attempting to recover the fairings?
No, this is not a capability of Astra.
Are these fairings new?
Yes
How’s the weather looking?
We don’t know Astra’s weather criteria for launch, but the weather in Kodiak doesn’t look too good.
This will be the:
– 1st test launch of Rocket 3.2
– 2nd test launch this year
Where to watch
Unfortunately Astra won’t have a live webcast for this launch, but they will post live updates on their Twitter.

What does all this mean?

Astra will launch its orbital-class rocket Rocket 3.2 from Launch Pad 3B, Pacific Spaceport Complex in Kodiak, Alaska. This launch can happen somewhere in the launch window that extends from December 7 to December 18 with a daily launch window opening up at 19:00 UTC and closing at 22:00 UTC. Rocket 3.2 will mark Astra’s second orbital launch attempt ever.

The Mission

After a failure of the guidance system and a following shut down of the engines in the early stages of the first stage burn of Rocket 3.1 back in September 2020, Astra is back at the launch pad. Rocket 3.2 is Astra’s second iteration of its Rocket 3 series and will again feature no payload as it is a test launch in Astra’s three launch campaign with the goal to finally reach orbit. There will only be additional sensors and instruments on the second stage that are required for data gathering during the different phases of the flight.

For the previous launch attempt Astra has set some goals they wanted to achieve. They aimed towards a nominal first stage burn and considered everything after main engine cut off (MECO) as additional goodies. They only achieved some of those milestones, but the data they’ve gathered was valuable enough that they might have raised their expectations for this launch. But since there is no information on that available at this time, we can only speculate.

Mission Timeline

T-1h15minStart of final pre-launch procedure
T-45minPropellant load begins
T-20minPropellant load complete
T-15minEntering terminal count
T-/+0sIgnition!
T+3sLift Off!
T+5sRoll program initiated
T+25sVehicle clears range
T+38sGravity turn
T+57sMaximum aerodynamic pressure (Max Q)
T+2min 3sBegin to throttle down the engines
T+2min 22sMain engine cut off (MECO)
T+2min 25sFairing separation
T+2min 29sStage separation
T+2min 33sSecond stage engine ignition
T+8min 32sSecond engine cut off (SECO)
T+8min 35sPayload deployment signal
Rocket 3.1 during lift off at launch pad 3B. (Credit: Astra/John Kraus)

The Rocket 3.2 Launch Vehicle

Rocket 3.2 is Astra’s second iteration of their third version of their small-sat launch vehicle. The Rocket 3 series is Astra’s orbital rocket series. With a height of 11.6 m (38 ft), a diameter of 1.32 m (4.3 ft) and a payload capacity of 25 kg to a 500 km Sun-Synchronous Orbit (SSO), it is in the same class of small-sat launch vehicles as Rocket Lab’s Electron.

Rocket 3.1 and the team before it got shipped off to the Pacific Spaceport Complex in Alaska. (Credit: Astra)

This two-stage rocket is powered by RP-1 and LOx. The first stage will make use of five electric-pump-fed Delphin engines that will produce a total thrust of ~145 kN (~32,500 lbf) at liftoff. The second stage is powered by a single pressure-fed Aether engine that will produce 3.1 kN (700 lbf) of thrust in a vacuum. Since Astra is a rather secretive company, they have not released any technical information about their engines, such as ISP (Specific Impulse), TWR (Thrust to Weight Ratio), or combustion chamber pressure. The aluminum body and tanks of Rocket 3.2 have a similarity to SpaceX’s Starship prototypes, with its welded stacked rings of stainless steel.

Another unique characteristic is that Astra’s Rocket 3 series rockets fit into a standard shipping container and can be towed by a truck. To set up the rocket on its mobile launch structure, it only takes a handful of ground support staff and about a week to go through vehicle checks, a wet dress rehearsal and the launch readiness review. Astra’s goal for the future is to bring the time required to set up the rocket down to under 24 hours. Therefore, it can meet the needs of some special customers who require a rapid launch schedule for their payloads.

Differences between Rocket 3.1 and Rocket 3.2

After the failure earlier this year, Astra held a post launch briefing in which they explained that there are only minor hardware differences between Rocket 3.1 and Rocket 3.2. The biggest change between the two different rockets will be in Software. Especially in the guidance software since this was the part of the rocket that failed during Rocket 3.1‘s launch.

Loss of Rocket 3.1

After liftoff of Astra’s first orbital launch attempt on September 12, 2020 at 04:19 UTC, the team on the ground send the signal to shut down the engines in the early stages of the first stage burn. This was caused by the rocket drifting off enough from the planned trajactory due to a software issue in the guidance system. Up until this point the rocket had performed nominally and also the Flight Termination System (FTS) worked as intended. Rocket 3.1 fell back down and exploded on impact. Due to the small size of Astra’s rockets they don’t require a pyrotechnical FTS, which would add complexity and cost to the rocket. Instead, they just shut down the engines, let it fall back down to earth and clean up whatever is left of the rocket.

Loss of Rocket 3.0

After a wet dress rehearsal as part of a pre-launch test in March, Astra’s Rocket 3.0 suffered from a catastrophic anomaly. This incident lead to the loss of Rocket 3.0. The anomaly was caused by a valve which was stuck open during de-tanking of the rocket. Fortunately, nobody was harmed during this incident, and only Astra’s hardware was damaged. Astra went back to the drawing board and tried to recreate the problem with the valve which has previously been tested thousands of times. After months of finding the root to the problem, Astra implemented three levels of redundancy in order to prevent another anomaly.

Additional Information on Astra

If you want to find out more about Astra, check out their Twitter or the previous Prelaunch Preview. There you will find more information on Astra’s company history and their team.

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