The federal auditors who keep tabs on NASA released a 44-page audit Wednesday of the space agency's efforts to build the giant new Space Launch System (SLS) rocket. It wasn't a rave review.

NASA bills SLS "America's next great rocket" able to carry astronauts beyond Earth orbit, back to the moon and eventually to Mars. Marshall Space Flight Center in Huntsville is leading SLS development just as it has led every NASA rocket program including the Saturn V moon rocket and the space shuttle.

There's a lot more to this story than one audit, including budget decisions made by political leadership in Washington that affected the resources Marshall and prime contractor Boeing had for the job. But here are 10 things we learned from the audit about how Marshall has managed SLS so far and how Boeing has performed.

1. Three NASA contracting officers exceeded their legal authority and approved millions of dollars more of spending than they should have. One contracting officer had authority to approve spending up to $2.5 million and authorized spending $318 million. Another with $1 million authority OK'd a maintenance contract modification worth $3.7 million. Auditors investigated and found these deals weren't made to benefit the NASA employees or contractors, but the total unauthorized spending was almost $321 million.

2. Building rockets to carry humans safely into deep space and back is about as hard as it gets. People don't compare tough jobs to "rocket science" for no reason. NASA hasn't developed a new deep space rocket program since the first Space Shuttle more than 37 years ago, and auditors acknowledged the difficultly and took it into account as they scored the progress of SLS.

3. NASA decided to build two SLS Core Stages at the same time - one for testing and one for flight. This new idea was supposed to save money and time on these big bottom stages that hold the rocket's engines, fuel tanks and electronics. Instead, auditors said it created "significant problems." For example, when a critical engine part failure delayed the test model, it delayed the flight version, too. And because NASA didn't require Boeing to report its development costs in detail, NASA still has no idea what a single Core Stage costs.

4. Because NASA and Boeing are still trying to finish the first two Core Stages, plans to build more are on hold. Because it takes 52 months from contract award to delivery, auditors say NASA can't get a third Core Stage built before 2023. That one will power the second SLS launch and the first with a crew. A third launch of a probe to Jupiter's moon Europa, where scientists think life might exist, could also be delayed beyond its planned launch in 2022.

This NASA diagram shows the SLS Core Stage with its engines, fuel tanks and connecting tanks. (NASA)

5. SLS is managed at Marshall, but the building is spread across America. Auditors counted more than 1,100 contractors in 43 states working on the rocket. Helpful for building a complex rocket on a schedule? Probably. Helpful for keeping congressional support? Definitely.

6. Auditors say Boeing "consistently underestimated" the work to be done and workforce required to do it, and the company has "been unable to consistently provide NASA realistic cost and schedule estimates." The audit blames the delays and cost increases largely on Boeing's "poor performance"

7. NASA's SLS contract with Boeing was "complex," auditors say, in what might be the understatement of the year so far. NASA pays Boeing for all labor costs, plus performance fees, completion milestone fees, and incentives to hold costs down. Boeing has already earned $265 million in award fees - or 89 percent of the total budgeted for the entire project.

8. In more bad money news, NASA has already spent $5.3 billion of its overall $6.2 billion budget for the two Core Stages. Both NASA and Boeing say they will bust the budget ceiling sometime between December and February 2019 - three years before Boeing's contract is supposed to end in 2021 and before delivery of a single Core Stage or electronics package. Congress will be asked for billions more.

9. Auditors found four major technical issues. SLS's command and control computer hardware and software is 18 months behind schedule. While installing rocket fuel tubing in the engine section of Core Stage 1, Boeing found contamination due to improper cleaning and had to replace 293 of 907 tubes causing months in delay. Boeing also uses the world's biggest welding tool to put the stage parts together. That tool was misaligned at one point and couldn't handle critical parts of the Core Stage causing a 9-month delay. And in 2016, Boeing found the machine wasn't meeting weld strength requirements causing another 3- to 5-month delay.

10. NASA has responded well to the audit. It has taken "positive steps to address management and procurement issues," auditors said. It has established five "Tiger Teams" of experts to improve performance at the Michoud Assembly Facility outside New Orleans where the welding and assembly is being done, and it has increased its number of performance reviews.

William Gerstenmaier, the space agency's associate administrator for human exploration and operations, filed NASA's response in a letter to auditors. SLS is "the largest launch system the history of spaceflight," he reminded auditors, and its design, development, manufacturing, testing and operations "are highly complex and represent a national investment in a long-term commitment to deep space exploration." NASA has been working to improve contract performance, Gerstenmaier said, and the auditors' report "is a fair assessment" of the agency's management so far.

NASA officially agreed with five of the audit's seven findings, and Gerstenmaier said the agency had already working many of these issues and "will learn from this experience in future procurements."