Scores 

A list of all team scores from the competition round are posted to this page 48 hours after the individual teams score sheets are emailed to the team directors. Scores are typically posted to this page the Thursday following the end of the competition window.
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PRACTICE ROUND 1

QUALIFICATION ROUND 1

PRACTICE ROUND 2

QUALIFICATION ROUND 2

PRACTICE ROUND 3

QUALIFICATION ROUND 3

TEAM TOTAL ROUND SCORES (ADVANCEMENT TO SEMIFINAL ROUND)

SEMIFINAL ROUND SCORES (ADVANCEMENT TO NATIONAL FINALS)

Practice Round 3 (PR3) Recap

SCENARIO OBSERVATIONS

SOLVING THE SCENARIO

​The task this round was to select the best launch vehicle that met the customer’s requirements while remaining below both the program’s $29,000,000 budget AND the selected launch vehicle’s mass lift capability limit.
 
It appears that a few teams had difficulty using the Launch Vehicle Performance Tables with twenty-nine teams exceeding the maximum weight limit of their rocket. Here is the maximum payload mass for a satellite placed into a 450 km circular orbit with an Inclination of 80° from each table:
 
Axxess                        1,879.828 kg
Cygnus                        1,933.673 kg
Sovereign II                 2,313.175 kg
 
If your team did not come up with these values, we recommend reviewing Appendix II of the Scenario Book and watching the following video on interpolation: https://www.youtube.com/watch?v=oiL2zvFaniY
 
Here’s a quick summary of each launch vehicle’s performance:
 
Axxess: This vehicle could not change its orbital altitude. This limited its CubeSats to only those satellites targeted for 450 km. The vehicle’s shock load (2,200 g’s) exceeded the satellite’s max allowable load (2,100 g’s), so a Shock Attenuation Kit was required. Axxess was the second lowest priced option.
 
Cygnus: This vehicle could place the satellite into the correct orbit and change the orbit altitude, but the vehicle’s acoustic load (135 dB) exceeded the satellite’s max allowable load (123 dB) and therefore, acoustic blankets were needed to protect the satellite. Cygnus had enough lift capability to handle this addition, reach the correct orbit, and change its orbit. However, the total cost of this launch service made it the third-best choice.
 
Sovereign II: This vehicle would appear to be the best choice because of its higher lift performance, lower price, and its ability to change the orbital altitude. In fact, it did turn out to be the most affordable option. The vehicle’s shock load (2,150 g’s) exceeded the satellite’s max allowable load (2,100 g’s), so a Shock Attenuation Kit was required. Its low price offset its high insurance rate. Its large 30U CubeSat dispenser lowered the launch cost even further due to the many CubeSats that could be flown.
 
Here are the best configurations and scores for each launch vehicle:
 
Axxess: Install a Shock Attenuation Kit. Install three 18U CubeSat dispensers. Deploy twenty-one 1U CubeSats and eleven 3U CubeSats at 450 km.
Best Possible Round Score: 90.412. (64 teams achieved this score).
 
Cygnus: Install acoustic blankets. Install two 24U CubeSat dispensers. Deploy fifteen 1U CubeSats and eleven 3U CubeSats at 450 km. Do not raise the orbit altitude.
Best Possible Round Score: 85.494. (8 teams achieved this score)
 
Sovereign II: Install a Shock Attenuation Kit. Install three 30U CubeSat dispensers. Deploy fifteen 1U CubeSats and eleven 3U CubeSats at 450 km. Raise the orbit altitude to 800 km. Deploy seven 6U CubeSats.
Highest Possible Round Score: 90.671. (21 teams achieved this score). Congratulations!
 
There are a few solutions that result in a score higher than 90.671. However, to reach these scores, the payload mass exceeded the max lift capability of the launch vehicle. In other words, the payload is overweight and on a real-world mission this would never be acceptable. Therefore, as stated on page 1 of the Scenario booklet, “...solutions that intentionally violate mission parameters …. may be rejected, or subject to penalties…” Teams that submitted these solutions had some of the CubeSats removed to bring the mass within the launch vehicle lift capability.
 
Number of teams selecting each launch vehicle: Axxess – 92, Cygnus – 50, Sovereign II – 71.
 
The average score for the round was 72.488.
 
Also, we noted that 34 teams installed Shock Attenuation Kits or acoustic blankets on the vehicles when they were not required. Installing this “extra” item raised the weight of the payload and reduced the number of CubeSats that could be flown on the mission. They also raised the price of the launch service, which lowered the possible team score.
 
Additional Observations
There seemed to be some confusion about CubeSats and CubeSat dispensers. Any size CubeSat can fit into any size canister as long as there is room for it. For example, a 6U CubeSat canister can hold one 6U CubeSat, or two 3U CubeSats, or six 1U CubeSats. A 48U canister can hold…. a lot of CubeSats! Each CubeSat has a target range of altitudes for its deployment, such as “500 km to 1,200 km” or “1,000 km to 1,600 km”. If a team deploys a CubeSat outside of its target altitude, they will receive no revenue from that CubeSat’s owner since the CubeSat cannot perform its mission at that altitude. We noted that a few teams did not include any CubeSats on their rocket or loaded several dispensers but only installed one CubeSat on the mission. Secondary satellites, like CubeSats, help to reduce the cost of the launch. Use them!
 
There were several solutions where teams did not use hundreds of kilograms of lift capability available in their rockets. These unused kg’s of lift could have been used to reach higher scores than the one available for the selected launch vehicle. We are not sure if the teams were just being conversative in their selection or that they lacked confidence in their lift calculation. If it was the latter, please review Appendix II in the scenario booklet.

ACADEMIC QUIZ

There was no academic quiz for PR3.
 
LOOKING AHEAD: PREPARING FOR QUALIFICATION ROUND 3
Qualification Round 3 (QR3) is scheduled for January 29 - February 1, 2026, and is another Launch Operation exercise, but with more options and more complications. Teams will select a launch vehicle to place a satellite/satellites into a predefined orbit. Each launch vehicle will have multiple options with each having its own performance, mass, price, and availability. The team’s job is to select the best combination to meet mission requirements, launch vehicle capability (launch mass), budget, and schedule. We identify the orbit where the satellite/satellites will be placed by the rocket. To prepare for QR3, we recommend that teams study the Round 3 Sample Scenario for Launch Operations and review how to calculate launch vehicle performance. Teams should review interpolation, and orbit altitude changes, to name a few. QR3 will be SIGNIFICANTLY MORE CHALLENGING than PR3.
 
There is an Academic Quiz for QR3. The QR3 Quiz Study Guide is available as part of the Training Materials. It is recommended that teams prepare by trying the launch operations sample scenario available at https://www.stellarxplorers.org/training.html. There are also additional third-party resources available (see link at the bottom of the training webpage).

IMPORTANT REMINDER – DESTRUCTION OF STLX COMPETITION MATERIALS ​

All copies of the PR3 competition scenario booklet, score sheets, STK VDFs, round emails, and team-produced documents must be collected and destroyed, or deleted, prior to the start of Qualification Round 3 on January 29, 2026. 

Continuing to hold onto materials from previous rounds, after the start of a new round, is a violation of the StellarXplorers Rule Book. Help us to ensure the integrity of the Competition by complying with these directions.   ​
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PROCEDURAL OBSERVATIONS

​​Team Numbers
Your team number (STLX12-XXXX) is very important during the StellarXplorers competition. It is how we track your results, store your files, and most importantly grade your solutions.

In PR3, 12 teams generated 13 instances of bad team numbers on either the start form or scenario component selection form. 

Our automated grading system looks for your team number in order to launch the scoring process. It looks for precisely 11 characters (STLX12-XXXX) to find and score your file. If there are more than or less than these 11 characters, the grader will abort the scoring process for all teams, and we must manually repair the incorrect team number. For example, say your team number is STLX12-0987.  Typing anything other than STLX12-0987 (even accidentally putting an extra space in front of the team number) will cause the grader to abort. The team number format is case sensitive, so be sure to use UPPERCASE letters. 

With regard to VDF uploads, it's important that teams follow the directions provided when it comes to doing their upload and naming their files, otherwise it will cause the grader to fail. The upload process generates the following unique file naming convention for team STLX12-0987: FirstName_LastName_UploadedFileName or QR1_STLX12-0987_QR1_STLX12-0987.vdf. The characters before the first underscore are whatever was entered in the First Name field, the next string of characters before the second underscore are from the Last Name field, and the remaining characters reflect the actual uploaded file's name. 
 
To help you avoid this mistake in the future, view the “Penalty Paper” to see a list of all the wrong ways (and the only right way) to provide your team number. This document also outlines other common penalties and how to avoid them. If you need clarification, contact [email protected].

PENALTY PAPER PDF

In all future rounds, teams will be penalized 5 POINTS each time they submit something with an incorrect team number. This includes the start form, academic quiz, solution upload/submission form, and/or VDF filename. It is imperative that you provide the correct team number in the correct STLX12-XXXX format.
 
And as always, include your team number in the subject line of all messages to us. It makes it easier for us to find you in our database and to file the information that you send to us.
 
Running Systems Tool Kit (STK)
As emphasized in prior communications, teams should load STK 13.0 Premium (which includes the Planetary Data Supplement) onto their computers and test that the software is operating successfully BEFORE STARTING THE ROUND. By “before” we mean days before, and also immediately prior to starting. We cannot guarantee staff support for last-minute technical issues, and teams will not be given any time relief if they do not have STK running on their computers at the start of the competition period. If needed, sample VDFs are available with our Training Materials, and can be used to test the software.
 
For those still needing licenses, please reach out to the StellarXplorers Program Staff as soon as possible to request them.

Changing STK Fixed Variables
Teams should not change any of the Fixed Variables in STK. These variables include but are not limited to: Start Time, Stop Time, Propagator, Step Size, Coord Epoch Time, etc. Additionally, teams should not change any component on the satellite, a target, or a facility on the ground. We use a team’s VDF to determine that team’s score. Therefore, these variables must remain the same so that we can fairly evaluate every team (this is why we impose severe penalties if these items are changed). Teams should only change the orbital elements of the satellite.
 
Several teams changed the Orbit Coord System and the Propagator. These changes can happen when a team uses the STK Orbit Wizard. If you use Orbit Wizard, be sure to check that the Fixed Variables, as shown in Appendix I of the scenario booklet, have not been changed.

Incomplete Submissions
Five teams failed to submit their scenario component selections required for StellarXplorers staff to score their solution.
  
​StellarXplorers Space Foundations Course (Nova Space)
Please make sure your team has access to the Nova Space learning platform BEFORE starting the round. Utilization of this course is instrumental in preparing for the academic quiz. If you need help accessing the course, please contact the StellarXplorers Program Office.
 
Confirmation Emails
Team directors will receive automated confirmation emails upon submission of a team’s start form, scenario component selections (in rounds 2 and 3), and academic quiz (when applicable). We are unable to provide automated confirmation emails for receipt of VDF submissions, but the team will receive a confirmation message on the screen once the file is uploaded successfully. 
 
Confirmation emails are sent to the email address provided in the “Team Director Email” field of the forms. To ensure there’s no delay in the delivery of these automated emails, competitors should pay close attention to the email address they are providing. There were several instances of incorrect email addresses this round.
 
QR3 Prep and Start Emails
QR3’s Prep Email will be sent out at 12:00 PM ET on Tuesday, January 20 and QR3’s Start Email will be sent out at 12:00 PM ET on Wednesday, January 28 (the day prior to the start of the competition window). To prevent delays in preparing for, or starting, the round, please contact [email protected] ASAP if you haven’t received the email by 2:00 PM ET on either day.

Finalizing Team Rosters
Team rosters are now final. No changes can be made to the roster other than removal of a member for the remainder of the competition.