Launch & Deployments?

I’ve moved into a new role on the Europa Clipper project, and if you’re not an engineer at NASA, it might sound like a bunch of jargon. What exactly does the “Flight System Launch and Deployments Lead” do?

First off, I’ve been on the Flight Systems Engineering Team for the past year. The Flight System is a term we use at JPL for the spacecraft (all subsystems together) plus the payload (the science instruments). Our team of ~15 people ensures that the high-level design of the spacecraft works, all subsystems work when related to each other, and that the spacecraft supports instrument needs. We basically make sure that all engineering topics work when put together as a cohesive system.

Our team has identified three key phases for the Flight System in the mission: Launch and Deployments, Jupiter Orbit Insertion, and Flybys (usually of Europa). These are all critical activities that the spacecraft has to complete to have a successful mission.

The Launch and Deployments Phase is the first phase in the mission and involves the spacecraft performing several activities to “ready itself” for the rest of the mission. The phase more or less starts when the Launch Vehicle (carrying Europa Clipper) lifts off from Earth and ends when the spacecraft is in a sound flight condition to make its trip to Jupiter.

The key activities that I’m working on include: establish communications once separated from the Launch Vehicle, ensure that the spacecraft is in a thermally safe orientation, vent and prime the propulsion system prior to its first use, deploy the solar arrays, charge the batteries as needed, and deploy other instrument related equipment, such as the magnetometer boom. The majority of these activities have to be completed autonomously, meaning that we have to design software to carry out all of these activities without ground operations.

It’s a lot of work, but it sure is fun! Here’s to getting a spacecraft safely to Jupiter, cheers!

 

Hello Europa, are you there?

Designing a communications system for a spacecraft is a basic, yet significant undertaking. All spacecraft must communicate, so the general practice is nothing new, but without a properly designed system, well, there could be just radio silence. Literally.

In addition to selecting the right hardware (radios, antennas, amplifiers), the Flight Software (FSW) must be designed to manage all the necessary functions. How should the hardware be configured to listen to commands? To send data to Earth? When should these configurations change?

Just imagine for a moment calling someone and the phone rings forever with no response. There is no voicemail system, just ringing. Forever. Does the other person’s phone not work? Are they asleep? Is their ringer on silent? Are they busy? The key is picking the right hardware (the phone) and designing the spacecraft’s software (the human’s actions) to “pick up and answer”.

This is what we’re doing on Europa Clipper right now. The hardware is already mostly selected (with some details to work), but the software is in an exciting early phase of development. Our team is thinking of how it should work for various scenarios including spacecraft emergencies and how new capabilities might fit into the mix.

 

Goodbye Cassini

Well, that’s it. The 13 year tour of Saturn, or 20 years if you count the time since launch, is over. During those final hours of the mission in the Mission Support Area (MSA) at NASA’s Jet Propulsion Laboratory, there was a mix of sadness and pride. I think it was the first time that I witnessed a live event in the ops room when there wasn’t jumping and cheering (like during MSL’s landing on Mars), instead there was silence. Everything went quiet when the signal was finally lost. Then our Project Manager, Earl Maize, and Spacecraft Operations Manager, Julie Webster, hugged.

I thought I’d share some pictures of the mission’s final moments with you.

 

Cassini’s End of Mission Schedule

A lot happened during the week of Cassini’s End of Mission on 9/15. Here’s the rundown of events and things to watch! (Of course after the fact since as you’re reading this the Cassini spacecraft is no more…)

The spacecraft’s final moments on Friday 9/15:

  • 1:37am PT: spacecraft configures for real-time data relay to Earth
  • 4:53am PT: spacecraft atmospheric entry begins, thrusters at 10% capacity
  • 4:54am PT: loss of signal at Earth, thrusters at 100% capacity and can no longer hold high-gain antenna pointed toward Earth; exact timing will very depending on Saturn’s atmosphere; Cassini spacecraft destruction will happen soon after this loss of signal

Cassini's final dive

Events on NASA TV, NASA/JPL’s YouTube channel and NASA’s main YouTube channel:

  • Wednesday 9/13 10am PT: Grand Finale pre-briefing
  • Thursday 9/14 1-2pm PT: Cassini Grand Finale NASA Social (w/ social media influencers)
  • Friday 9/15 4am PT: Grand Finale live commentary (90 minutes)
  • *Loss of signal from Cassini Spacecraft in Saturn’s atmosphere = ~4:54am PT*
  • Friday 9/15 6:30am PT: post-mission news briefing

Other TV airings:

Don’t Rain on My Solar Arrays

I’m sitting in a conference room at the Applied Physics Laboratory (APL). One entire wall, specifically one of the longer walls of the rectangular room, is a window. I got myself a prime seat at the table facing the window. Clutch. Now I can look outside as I gather my thoughts during the meeting. Those of you that work in offices know how important windows are for sanity.

It’s raining outside. This is actually quite nice for me being from LA where it never rains. At JPL, I’m used to walking between buildings underneath the burning Sun. This is a nice change of pace.

As it rains outside, we discuss the Solar Arrays for the Europa Clipper Spacecraft inside. JPL and APL have teamed up for the Spacecraft design, each of us managing various parts. So, what’s the topic of discussion for the Solar Arrays today? Requirements. Good ole requirements. As Preliminary Design Review (PDR) season approaches, lower-level teams from all over the Project have to get their requirements reviewed and approved. (The higher-level teams already have baselined requirements at this phase.) With a solid set of requirements, we can all pass through this gate review to the next phase of development, the final design.

Right now our design is only preliminary. We long ago chose to use solar power over RTGs, but now we have a much more realistic Solar Array design. From the mechanical mounting to electrical interfaces, the design is maturing every day. This requirements review brings us one step closer to PDR and to building a real life Spacecraft.