Elon Musk has big plans for its company SpaceX, as big as a manned Mars mission in no less than eight years. But after a series of failed launches, many are starting to question SpaceX's capabilities. After all, carrying humans to Mars is an entirely different ballgame than transporting cargo to the International Space Station (ISS) in low-Earth orbit.

And even ISS missions for NASA seem to be difficult to accomplish for SpaceX, given its failed launch last year.

In June 2015, a SpaceX Falcon 9 rocket launched from Cape Canaveral loaded with supplies for the ISS. A few minutes after takeoff, the rocket blew up. From then on, people seemed unsure about the future of SpaceX.

Not to mention that the failed resupply mission known as CRS-7 caused delays for future missions to the station and lost NASA a new airlock it had developed for commercial spacecraft bringing humans to the station, Quartz.com reports.

But most of all, the failed mission represented a "major hurdle" for the company, which has been working relentlessly for years to develop low-cost transit to space.

Just recently, NASA negotiated discounted mission prices with SpaceX after the failed mission.

After a series of failures, how does SpaceX maintain peace with its key patrons?

SpaceX's Relationship with NASA

Quartz.com provided a glimpse of a 2015 audit document that shows how SpaceX maintains the confidence of its biggest client.

1. Forfeiture of launch fee

SpaceX's resupply contracts with NASA are split into three - preparation, launch and mission completion. The explosion of the Falcon 9 rocket meant that SpaceX has forfeited one-third of the launch fee.

2. Price lock-ins

According to document, SpaceX guarantees launch prices regardless of delays, which allows NASA to save more on than what was quoted.

3. Add-ons

SpaceX provides NASA with extra services at no cost. For instance, the company offered to ramp up the electrical power of its Dragon spacecraft so it could handle three-times more cargo.

4. Come clean

After the failed Falcon 9 mission, SpaceX conducted an internal investigation that pointed towards a failed strut assembly, which was manufactured by a subcontractor.

5. Shift manufacturing processes to address NASA concerns

In response to NASA's concerns about SpaceX's "systems engineering and management practices," the company has reorganized its quality control systems and the management of technicians' work, as well as conducted tests on individual rocket components.

In a statement published on LA Times, SpaceX said that it had successfully managed its contract with NASA, reducing costs and financial risks. The company also maintains that it has launched seven times successfully since the incident.